Methods of treating Giardia lamblia

ABSTRACT

The present invention provides methods for treating Pneumocystis carinii pneumonia and Giardia lamblia in a subject in need of such treatment. The methods comprises administering to the subject a compound of Formula I: ##STR1## wherein: X and Y are located in the para or meta positions and are selected from the group consisting of H, loweralkyl, loweralkoxy, and ##STR2## wherein: each R 1  is independently selected from the group consisting of H, loweralkyl, alkoxyalkyl, hydroxyalkyl, aminoalkyl, alkylaminoalkyl, cycloalkyl, aryl, or alkylaryl or two R 1  groups together represent C 2  -C 10  alkyl, hydroxyalkyl, or alkylene, or two R 1  groups together represent ##STR3## wherein m is from 1-3 and R 7  is H or --CONHCR 8  NR 9  R 10 , wherein R 8  is loweralkyl, and R 9  and R 10  are each independently selected from the group consisting of H and lower alkyl; 
     R 2  is H, hydroxy, loweralkyl, alkoxyalkyl, hydroxyalkyl, aminoalkyl, alkylaminoalkyl, cycloalkyl, aryl, or alkylaryl; 
     n is a number from 0 to 2; 
     R 3  and R 4  are each independently selected from the group consisting of H, loweralkyl, loweralkoxy, alkylaryl, aryl, oxyaryl, aminoalkyl, aminoaryl, or halogen; and 
     R 5  and R 6  are each independently selected from the group consisting of H, loweralkyl, aryl, alkylaryl, aminoalkyl, aminoaryl, halogen, oxyalkyl, oxyaryl, or oxyarylalkyl; or a phamaceutically acceptable salt thereof. The compound of Formula I is administered in an amount effective to treat the condition. 
     The present invention also provides compounds useful for the treatment of Pneumocystis carinii pneumonia and Giardia lamblia.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.08/305,823, filed 13 Sep., 1994, now U.S. Pat. No. 5,521,189 which is acontinuation-in-part of U.S. patent application Ser. No. 08/238,766,filed 06 May, 1994, the disclosures of which are incorporated herein byreference in their entirety.

The present invention was made with Government support under GrantNumber UO1-A1-3363 from the National Institutes of Health. TheGovernment has certain rights to this invention.

FIELD OF THE INVENTION

The present invention relates to methods of combatting Pneumocystiscarinii Pneumonia with dicationic compounds and novel compounds usefultherefor. Specifically, the present invention relates to methods ofcombatting Pneumocystis carinii pneumonia with bis-aryl pyrimidine andnovel bis-aryl pyrimidines useful therefor.

BACKGROUND OF THE INVENTION

Pentamidine is used for the treatment of Pneumocystis carinii pneumonia,or "PCP". The importance of pentamidine has dramatically escalatedrecently due to the marked increase of patients suffering from PCP. Theincrease in the afflicted patient population is an unfortunateconsequence of the increasing presence of the Acquired ImmunodeficiencySyndrome ("AIDS"). It is now estimated that approximately 70 percent ofAIDS patients contract PCP. Because of the high incidence of PCP in AIDSpatients, pentamidine has found utility not only in the treatment ofPCP, but also as prophylaxis, in preventing or delaying the initialonset or recurrence of PCP, especially in AIDS patients. Currently,pentamidine is most commonly administered as a therapeutic agent byintravenous infusion and as a prophylactic agent by aerosol dosage.

However, an unfortunate side effect of pentamidine is its toxicity. Somefatalities have been attributed to severe hypotension, hypoglycemia, andcardiac arrhythmias in patients treated with pentamidine. Contrawise,insufficient dosage may result in dissemination of disease beyond thelung, an occurrence which is associated with a poor prognosis.

Pentamidine is presently in limited use because of cost and toxicity.Therapeutic drug monitoring is not used because of the cost andcomplexity of the currently available assay techniques which require theextraction of plasma and High Performance Liquid Chromatographyanalysis. As a result, the toxicity of pentamidine is a significantconcern, which is driving the market toward the development ofpentamidine substitutes capable of avoiding or minimizing theundesirable side effects associated with the use of pentamidine.Accordingly, it is an object of the present invention to provide newmethods of treating Pneumocystis carinii pneumonia.

SUMMARY OF THE INVENTION

As a first aspect, the present invention provides a method of treatingPneumocystis carinii pneumonia. The method includes administering to asubject in need of such treatment, a compound of Formula I: ##STR4##wherein: X and Y are located in the para or meta positions and areselected from the group consisting of H, loweralkyl, loweralkoxy, and##STR5## wherein: each R₁ is independently selected from the groupconsisting of H, loweralkyl, alkoxyalkyl, hydroxyalkyl, aminoalkyl,alkylaminoalkyl, cycloalkyl, aryl, or alkylaryl or two R₁ groupstogether represent C₂ -C₁₀ alkyl, hydroxyalkyl, or alkylene, or two R₁groups together represent ##STR6## wherein m is from 1-3 and R₇ is H or--CONHR₈ NR₉ R₁₀, wherein R₈ is loweralkyl, and R₉ and R₁₀ are eachindependently selected from the group consisting of H and lower alkyl;

R₂ is H, hydroxy, loweralkyl, alkoxyalkyl, hydroxyalkyl, aminoalkyl,alkylaminoalkyl, cycloalkyl, aryl, or alkylaryl;

n is a number from 0 to 2 (where n is 0, the bond is direct covalentlinkage between the rings);

R₃ and R₄ are each independently selected from the group consisting ofH, loweralkyl, loweralkoxy, alkylaryl, aryl, oxyaryl, aminoalkyl,aminoaryl, or halogen; and

R₅ and R₆ are each independently selected from the group consisting ofH, loweralkyl, aryl, alkylaryl, aminoalkyl, aminoaryl, halogen,oxyalkyl, oxyaryl, or oxyarylalkyl; or a phamaceutically acceptable saltthereof. The compounds of Formula I are administered in an amounteffective to treat Pneumocystis carinii pneumonia.

As a second aspect, the present invention provides compounds useful forthe treatment of Pneumocystis carinii pneumonia The compounds have thestructural Formula I, described above. Currently preferred compounds ofFormula I include, but are not limited to,2,4-bis-(4-guanylphenyl)pyrimidine,2,4-bis-(4-imidazolin-2-yl)pyrimidine,2,4-bis-[(tetrahydropyrimidinyl-2-yl)phenyl]Pyrimidine,2-(4-[N-i-propylguanyl]phenyl)-4-(2-methoxy4-[N-i-propylguanyl]phenyl)pyrimidine,and pharmaceutically acceptable salts thereof.

As a third aspect, the present invention provides a method of treatingGiardia lamblia in a patient in need of such treatment. The methodincludes administering to a patient in need of such treatment, acompound of Formula I above, in an amount effective to treat Giardialamblia.

As a fourth aspect, the present invention provides a method of treatingCryptosporidium parvum in a patient in need of such treatment. Themethod includes adminstering to a patient in need of such treatment, acompound of Formula I above, in an amount effective to treatCryptosporidium parvum.

The foregoing and other objects and aspects of the present invention areexplained in detail in the specification set forth hereinbelow.

DETAILED DESCRIPTION OF THE INVENTION

The term "loweralkyl," as used herein, refers to C₁ to C₄ linear orbranched alkyl, such as methyl, ethyl, propyl, butyl, isopropyl,sec-butyl, and tert-butyl. Methyl, ethyl, and isopropyl are currentlypreferred. The term "loweralkoxy," as used herein, refers to C₁ to C₄linear or branched alkoxy, such as methoxy, ethoxy, propyloxy, butyloxy,isopropyloxy, and tbutyloxy. Methoxy is currently preferred.

As noted above, the methods of the present invention are useful fortreating Pneumocystis carinii pneumonia and Giardia lamblia. The methodsof the present invention are useful for treating these conditions inthat they inhibit the onset, growth, or spread of the condition, causeregression of the condition, cure the condition, or otherwise improvethe general well-being of a subject inflicted with, or at risk ofcontracting the condition.

Subjects to be treated by the methods of the present invention aretypically human subjects although the methods of the present inventionmay be useful with any suitable subject known to those skilled in theart.

As noted above, the present invention provides pharmaceuticalformulations comprising the aforementioned compounds of Formula I, orpharmaceutically acceptable salts thereof, in pharmaceuticallyacceptable carriers for aerosol, oral, and parenteral administration asdiscussed in greater detail below. Also, the present invention providessuch new compounds or salts thereof which have been lyophilized andwhich may be reconstituted to form pharmaceutically acceptableformulations for administration, as by intravenous or intramuscularinjection.

Obviously, the therapeutically effective dosage of any specificcompound, the use of which is in the scope of present invention, willvary somewhat from compound to compound, patient to patient, and willdepend upon the condition of the patient and the route of delivery. As ageneral proposition, a dosage from about 0.1 to about 50 mg/kg will havetherapeutic efficacy, with still higher dosages potentially beingemployed for oral and/or aerosol administration. Toxicity concerns atthe higher level may restrict intravenous dosages to a lower level suchas up to about 10 mg/kg, all weights being calculated based upon theweight of the active base, including the cases where a salt is employed.Typically a dosage from about 0.5 mg/kg to about 5 mg/kg will beemployed for intravenous or intramuscular administration. A dosage fromabout 10 mg/kg to about 50 mg/kg may be employed for oraladministration. The duration of the treatment is usually once per dayfor a period of two to three weeks or until the Pneumocystis cariniipneumonia is essentially controlled. Lower doses given less frequentlycan be used to prevent or reduce the incidence of recurrence of theinfection.

In accordance with the present method, a compound of Formula I, or apharmaceutically acceptable salt thereof, may be administered orally orthrough inhalation as a solid, or may be administered intramuscularly orintravenously as a solution, suspension, or emulsion. Alternatively, thecompound or salt may also be administered by inhalation, intravenouslyor intramuscularly as a liposomal suspension. When administered throughinhalation the compound or salt should be in the form of a plurality ofsolid particles or droplets having a particle size from about 0.5 toabout 5 microns, preferably from about 1 to about 2 microns.

Besides providing a method for treating Pneumocystis carinii pneumonia,the compounds of Formula I also provide a method for prophylaxis againstPneumocystis carinii pneumonia in an immunocompromised patient, such asone suffering from AIDS, who has had at least one episode ofPneumocystis carinii pneumonia, but who at the time of treatment is notexhibiting signs of pneumonia. As Pneumocystis carinii pneumonia is anespecially potentially devastating disease for immunocompromisedpatients it is preferable to avoid the onset of Pneumocystis cariniipneumonia, as compared to treating the disease after it has becomesymptomatic. Accordingly, the present invention provides a method forthe prophylaxis against Pneumocystis carinii pneumonia comprisingadministering to the patient a prophylactically effective amount of acompound of Formula I or a pharmaceutically acceptable salt thereof. Theforms for administration of the compound or salt in accordance with thismethod may be the same as utilized for the purpose of actually treatinga patient suffering from Pneumocystis carinii pneumonia.

An additional useful aspect of the present invention is a method forprophylaxis against even an initial episode of Pneumocystis cariniipneumonia in an immunocompromised patient who has never experienced anepisode of Pneumocystis carinii pneumonia. In this respect, a patientwho has been diagnosed as being immunocompromised, such as one sufferingfrom AIDS or ARC (AIDS related complex), even before the onset of aninitial episode of Pneumocystis carinii pneumonia, may avoid or delaysuffering from the infection by having administered a prophylacticallyeffective amount of a compound of Formula I or a pharmaceuticallyacceptable salt thereof. The compound or salt may be administered in thesame fashion as in the treatment of patients suffering from Pneumocystiscarinii pneumonia.

The present invention also provides new pharmaceutical compositionssuitable for intravenous or intramuscular injection. The pharmaceuticalcompositions comprise a compound of Formula I, or a pharmaceuticallyacceptable salt thereof, in any pharmaceutically acceptable carrier. Ifa solution is desired, water is the carrier of choice with respect towater-soluble compounds or salts. With respect to the water-insolublecompounds or salts, an organic vehicle, such as glycerol, propyleneglycol, polyethylene glycol, or mixtures thereof, may be suitable. Inthe latter instance, the organic vehicle may contain a substantialamount of water. The solution in either instance may then be sterilizedin any suitable manner, preferably by filtration through a 0.22 micronfilter. Subsequent to sterilization, the solution may be filled intoappropriate receptacles, such as depyrogenated glass vials. Of course,the filling should be done by an aseptic method. Sterilized closures maythen be placed on the vials and, if desired, the vial contents may belyophilized.

In addition to compounds of Formula I or their salts, the pharmaceuticalcompositions may contain other additives, such as pH adjustingadditives. In particular, useful pH adjusting agents include acids, suchas hydrochloric acid, bases or buffers, such as sodium lactate, sodiumacetate, sodium phosphate, sodium citrate, sodium borate, or sodiumgluconate. Further, the compositions may contain microbialpreservatives. Useful microbial preservatives include methylparaben,propylparaben, and benzyl alcohol. The microbial preservative istypically employed when the formulation is placed in a vial designed formultidose use. Of course, as indicated, the pharmaceutical compositionsof the present invention may be lyophilized using techniques well knownin the art.

In yet another aspect of the present invention, there is provided aninjectable, stable, sterile composition comprising a compound of FormulaI, or a salt thereof, in a unit dosage form in a sealed container. Thecompound or salt is provided in the form of a lyophilizate which iscapable of being reconstituted with a suitable pharmaceuticallyacceptable carrier to form a liquid composition suitable for injectionthereof into man. The unit dosage form typically comprises from about 10mg to about 10 grams of the compound or salt. When the compound or saltis substantially water-insoluble, a sufficient amount of emulsifyingagent which is physiologically acceptable may be employed in sufficientquantity to emulsify the compound or salt in an aqueous carrier. Onesuch useful emulsifying agent is phosphatidyl choline.

Other pharmaceutical compositions may be prepared from thewater-insoluble compounds of Formula I, or salts thereof, such asaqueous base emulsions. In such an instance, the composition willcontain a sufficient amount of pharmaceutically acceptable emulsifyingagent to emulsify the desired amount of the compound of Formula I orsalt thereof. Particularly useful emulsifying agents includephosphatidyl cholines, and lecithin.

Further, the present invention provides liposomal formulations of thecompounds of Formula I and salts thereof. The technology for formingliposomal suspensions is well known in the art. When the compound ofFormula I or salt thereof is an aqueous-soluble salt, useingconventional liposome technology, the same may be incorporated intolipid vesicles. In such an instance, due to the water solubility of thecompound or salt, the compound or salt will be substantially entrainedwithin the hydrophilic center or core of the liposomes. The lipid layeremployed may be of any conventional composition and may either containcholesterol or may be cholesterol-free. When the compound or salt ofinterest is water-insoluble, again employing conventional liposomeformation technology, the salt may be substantially entrained within thehydrophobic lipid bilayer which forms the structure of the liposome. Ineither instance, the liposomes which are produced may be reduced insize, as through the use of standard sonication and homogenizationtechniques.

Of course, the liposomal formulations containing the compounds ofFormula I or salts thereof, may be lyophilized to produce a lyophilizatewhich may be reconstituted with a pharmaceutically acceptable carrier,such as water, to regenerate a liposomal suspension.

Pharmaceutical formulations are also provided which are suitable foradministration as an aerosol, by inhalation. These formulations comprisea solution or suspension of the desired compound of Formula I or a saltthereof or a plurality of solid particles of the compound or salt. Thedesired formulation may be placed in a small chamber and nebulized.Nebulization may be accomplished by compressed air or by ultrasonicenergy to form a plurality of liquid droplets or solid particlescomprising the compounds or salts. The liquid droplets or solidparticles should have a particle size in the range of about 0.5 to about5 microns. The solid particles can be obtained by processing the solidcompound of Formula I, or a salt thereof, in any appropriate mannerknown in the art, such as by micronization. Most preferably, the size ofthe solid particles or droplets will be from about 1 to about 2 microns.In this respect, commercial nebulizers are available to achieve thispurpose.

Preferably, when the pharmaceutical formulation suitable foradministration as an aerosol is in the form of a liquid, the formulationwill comprise a water-soluble compound of Formula I or a salt thereof,in a carrier which comprises water. A surfactant may be present whichlowers the surface tension of the formulation sufficiently to result inthe formation of droplets within the desired size range when subjectedto nebulization.

As indicated, the present invention provides both water-soluble andwater-insoluble compounds and salts. As used in the presentspecification, the term "water-soluble" is meant to define anycomposition which is soluble in water in an amount of about 50 mg/mL, orgreater. Also, as used in the present specification, the term"water-insoluble" is meant to define any composition which hassolubility in water of less than about 20 mg/mL. For certainapplications, water soluble compounds or salts may be desirable whereasfor other applications water-insoluble compounds or salts likewise maybe desirable.

Examples of compounds exemplary of Formula (I) above include, but arenot limited to:

(1) 2,4-bis-(4-guanylphenyl)-pyrimidine,

(2) 2,4-bis-(4-imidazolin-2-yl)-pyrimidine,

(3) 2,4-bis-[(tetrahydropyrimidinyl-2-yl)phenyl]pyrimidine,

(4)2-(4-[N-i-propylguanyl]phenyl)-4-(2-methoxy-4-[N-i-propylguanyl]phenyl)pyrimidine.

Compounds employed in carrying out the present invention may be preparedin accordance with techniques known to those skilled in the art (see,e.g., U.S. Pat. No. 4,933,347), particularly in light of the disclosureand examples set forth below.

As indicated, the compounds used in the present invention may be presentas pharmaceutically acceptable salts. Such salts include the gluconate,lactate, acetate, tartarate, citrate, phosphate, borate, nitrate,sulfate, and hydrochloride salts.

The salts of the present invention may be prepared, in general, byreacting two equivalents of the pyrimidine base compound with thedesired acid, in solution. After the reaction is complete, the salts arecrystallized from solution by the addition of an appropriate amount ofsolvent in which the salt is insoluble.

Methods of combating Giardia lamblia with the compounds of Formula Iabove are carried out in essentially the same manner as given above, andpharmaceutical formulations of the compounds of Formula I for combatingGiardia lamblia are prepared in essentially the same manner as givenabove.

Methods of combating Cryptosporidium parvum with the compounds ofFormula I above are carried out in essentially the same manner as givenabove, and pharmaceutical formulations of the compounds of Formula I forcombating Cryptosporidium parvum are prepared in essentially the samemanner as given above.

The compounds of the present invention are useful not only in methodsfor treating Pneumocystis carinii pneumonia, Giardia lamblia, andCryptosporidium parvum, but also in methods of inihibiting enzymes suchas topoisomerase. The compounds of Formula I are particularly useful forinhibiting topoisomerase II. See, S. Doucc-Racy, et al., Proc. Natl.Acad. Sci. USA 83: 7152 (1986).

As noted above, the compounds of the present invention may be preparedaccording to methods known in the art. For example, compounds of FormulaI above may be prepared by first preparing an appropriate intermediate,such as 2,4-bis(4-bromophenyl)pyrimidine. The intermediate is preparedby the base promoted condensation of 4-bromobenzamidine and1-dimethylamino-3-dimethylimmonio-1-(4-bromophenyl)-l-propene, accordingto the method of R. Wagner, et al., Chem. Bet. 104:2975 (1971). Thebis-nitrile is readily obtainable by reacting copper(I) cyanide with thethus prepared intermediate in refluxing DMF according to the standardtechniques. See, J. Spychala, et al., European J. Med. Chem. 29:363(1994). The bis-nitrile is converted to the imidate ester by the Pinnermethodology, according to B. Das, et al., J. Med. Chem. 20:1219 (1977).The compounds of Formula I are obtained from the imidate ester accordingto known techniques. See, Das, et al., supra. Scheme 1 below, outlinesthe foregoing procedure for preparing compounds of Formula I. ##STR7##

The present invention is explained in greater detail in the followingexamples. As used herein,, "mp" means melting point, "NMR" means nuclearmagnetic resonance, "MHz" means megahertz, "FAB" means fast atomicbombardment, "EI" means electon ionization, "IR" means infrared spectra,"MS" means mass spectroscopy, "Hz" means hertz, "g" means grams, "mL"means milliliters, "L" means liters, "hr" means hours, "C" means degreesCentigrade, "DMSO" means dimethyl sulfoxide, "DMF" means dimethylformamide, and "m/e" means mass divided by charge. These Examples areillustrative and are not to be taken as limiting of the invention.

EXAMPLE 1 Preparation of1-Dimethylamino-3-dimethylimonio-l-(4-bromophenyl)-1-propene perchlorate

Using the method of A. Holy, et al., Collect. Czech. Chem. Comm. 30:4127(1965), freshly distilled phosphorus oxychloride (122.8 g, 0.8 mole) isadded, dropwise, to a cooled and stirred solution of 73 g (1.0 mole) drydimethylformamide in 150 mL dry chloroform. The solution turnsreddish-pink during addition and is stirred for 1 hr.4-Bromoacetophenone (39.8 g, 0.2 mole) in 100 mL of dry chloroform isadded to the previously prepared solution and the mixture is heated to50°-60° C. for 3 hr. After the mixture is allowed to cool it is pouredinto stirred ice cold water (external cooling required). The aqueoussolution is extracted with 100 mL ether, after which aqueousdimethylamine (40% solution) is added slowly, with cooling, to theaqueous layer. The resulting thick yellow precipitate is filtered and isresuspended in 200 mL of water. A solution of sodium perchlorate (34 g,0.28 mole) in 50 mL water is added to the suspension, and a thick yellowprecipitate is obtained. The precipitate is filtered and dried in vacuoat 50° C. for 12 hr. The yellow solid is dissolved in 400 mL of boilingabsolute ethanol. After cooling, the off-white crystalline precipitateis filtered, washed with dry ether and dried in vacuo at 50° C. for 24hr. Yield=50.5 g (66%).

Characterization: mp=160°-62° C. IR(KBr): 2391, 1630, 1561, 1394, 836cm⁻¹. ¹ H-NMR (DMSO-d₆): 7.76 (d, 2H, j=8 Hz), 7.27 (d, 2H, j=8 Hz),6.91 (d, 1H, j=12 Hz), 3.31 (s, 3H), 3.13 (s, 3H), 3.11 (s, 3H), 2.87(s, 3H). ¹³ C-NMR (DMSO-d₆): 169.4, 160.9. 131.0, 130.8, 130.5, 123.9,91.8, 45.8, 42.8, 40.8, 38.1. MS m/e: 281 (M⁺ --HCLO₄).

EXAMPLE 2 Preparation of 4-Bromobenzamidine benzenesulfonate

A stirred mixture of 4-bromobenzonitrile (36.4 g, 0.2 mole) and ammoniumbenzenesulfonate (45 g, 0.26 mole) is gradually heated to 260°-279° C.(bath temp.) for 2.5 hr; at this temperature the melt becomes a clearliquid (both boiling and sublimation of the mixture is observed). Thebath is removed and the melt is slowly and carefully added to 600 mL ofacetone to dissolve any unreacted nitrile and also to prevent the meltfrom becoming a hard solid mass. Any lumps remaining are broken and thesolid is filtered. The solid is thoroughly ground and then slurried withwater to remove any excess ammonium benzene sulfonate and filtered. Thesolid is again slurried with acetone and filtered, washed with dry etherand dried in vacuo at 100° C. for 12 hr. Yield: 33 g (51% based onrecovered nitrile). The acetone extract yielded unreactedp-bromobenzonitrile (12.8 g).

Characterization: mp 253° C. (literature value: 250°-260° C.). IR(KBr) :3325, 3126, 1681, 1597 cm⁻¹. ¹ H-NMR (DMSO-d6): 9.15 (s, 4H), 7.8 (q,4H), 7.32 (m, 2H), 7.23 (m,3H). ¹³ C-NMR (DMSO-d6): 164.8, 147.8, 131.9,130.0, 128.4, 127.5, 127.2, 125.3.

EXAMPLE 3 Preparation of 4-Bromobenzamidine

Sodium hydroxide (6-7 mL of 5 M) is added to a stirred mixture of theamidine salt (3.57 g, 0.01 mole) (produced as in Example 2) in 10 mL ofwater. Stirring is maintained for 10 min. The solid is filtered, washedwith water, and dissolved in 50 mL of acetone. Thereafter, the dissolvedsolid is treated with charcoal, filtered, and the acetone removed underreduced pressure. The resulting white crystalline solid is washed withdry ether and dried in vacuo at 40° C. for 12 hr. Yield: 1.5 g (75%).

Characterization: mp=168°-169° C. (literature value=159° C.). IR (KBr):3420, 3326, 3240, 3050, 1649 cm⁻¹. ¹ H-NMR (DMSO-d₆, 45° C.): 7.74 (d,2H, j=8.2 Hz), 7.62 (d, 2H, J=8.2 Hz) 6.43 (br, 3H). ¹³ C-NMR (DMSO-d₆,45° C.) 161.3, 135.4, 130.7, 128.5, 123.0. MS m/e: 198 (M⁺).

EXAMPLE 4 Preparation of 2,4-Bis(4-bromophenyl)-pyrimidine

Sodium ethoxide (0.055 mole), prepared from 1.26 g sodium and 70 mLethanol, is added to a stirred mixture of p-bromobenzamidine benzenesulfonate (10.7 g, 0.03 mole) and1-dimethylamino-3-dimethylimonio-l-(4-bromophenyl)-1-propene perchlorate(8.4 g, 0.022 mole) in 100 mL of absolute ethanol. After stirring for 30min at room temperature a further equivalent of sodium ethoxide is addedand the mixture is heated under reflux with efficient stirring for 3 hr.The solvent is removed under reduced pressure, and the yellow residue istriturated with 100 mL water. The resulting solid is filtered and washedwith water. The yellow cake, after drying, is recrystallized fromether:hexane (2:3) to give colorless needles. Yield: 3.65 g (86%).

Characterization: mp=165°-166° C. IR (KBr): 1585, 1578, 1555, 816, 765cm⁻¹. ¹ H-NMR (CDCl₃, 35° C.): 8.71 (d, 1H, j=5.5 Hz), 8.39(d, 2H, j=8.5Hz), 8.25 (d, 2H, j=8.5 Hz), 7.63 (d, 2H, j=6.7 Hz), 7.6 (d, 2H, j=6.7Hz), 7.5 (d, 1H, j=5.5 Hz). ¹³ C-NMR (CDCl₃, 35° C.): 163.9, 162.8,158.0, 136.7, 135.7, 132.2, 131.7, 129.9, 128.6, 125.6, 114.3. MS m/e:390 (M+).

EXAMPLE 5 2,4-Bis(4-cyanophenyl)-pyrimidine

A mixture of 2,4-bis(4-bromophenyl) pyrimidine (7.8 g, 0.02 mole) andcopper (I) cyanide (4.45 g, 0.05 mol) in 50 mL dry dimethylformamide isheated under reflux for 30-35 hr, during which time the color of themixture changes to dark brown. When the mixture is poured into 300 mLice cold water, a brown solid precipitated. The mixture is stirred for 3hr with 300 mL 10% NaCN solution. The solid is filtered, washed withwater (1.5 L) and dried. The brown solid cake is placed in a soxlatedevice and extracted with boiling acetone for 36 hr. The solvent isremoved and the light brown solid is chromatographed over neutral Al₂O₃. Elution with acetone:hexane (7:3) (20×50 mL fractions) andevaporation of the solvent yields pale yellow fluffy needles which aredried in vacuo at 100° C. for 6-7 hr. Yield: 2.7 g

Characterization: mp 239°-242° C. Elemental analysis calculated for C₁₈H₁₀ N₄ : C: 76.56, H: 3.57, N: 19.84; found: C: 76.50, H, 3.64, N:19.75. IR (KBr): 2223, 1580, 1550, 831, 798 cm⁻¹. ¹ H-NMR (DMSO-d₆, 35°C.:) 9.08 (d, 1H, j=5.4 Hz), 8.65 (d, 2H, j=8.8 Hz), 8.5 (d, 2H, j=8.3Hz), 8.15 (d, 2H, j=5.4 Hz), 8.03 (d, 2H, j=8.8 Hz), 8.01 (d, 2H, j=8.3Hz). ¹³ C-NMR (DMSO-d₆, 35° C.): 161.7, 161.2, 159.0, 140.8, 139.8,139.6, 132.3, 128.2, 127.7, 118.2, 118.0, 116.3, 113.4, 113.1. MS m/e:282 (M⁺).

EXAMPLE 6 Preparation of 2,4-Bis-(4-guanylphenyl)-pyrimidinehydrochloride

The bis-nitrile of Example 5 (2.8 g, 0.011 mole) is suspended in 250 mLabsolute ethanol and cooled in an ice-salt bath. After dry HCl gas ispassed through it the compound is dissolved. The clear yellow solutionis placed in a pressure bottle and left for 12 hr with occasionalshaking. The imidate ester hydrochloride is filtered, washed with dryether and dried in vacuo to yield 4.2 g. The dried imidate ester isshown to be free of contamination by the bis-nitrile starting materialby its IR spectrum.

Dry ammonia is passed through a cold suspension of 2.1 g (0.0043 mole)of the imidate ester in 50 mL absolute ethanol until saturated. Themixture is shaken for 2 days after which the solvent is removed, theresulting solid suspended in water, and made basic to a pH greater than9 with 10% NaHCO₃. The free base which precipitates is filtered anddried in vacuo at 70° C. for 12 hr. The off -white solid isrecrystallized from boiling ethanol. Yield: 1.1 g (69%).

Characterization: mp=237°-39° C. Elemental analysis calculated for C₁₈H₁₆ N₆.0.5H2O: C: 66.42, H: 5.06, N: 25.82; found: C: 66.46, H: 5.04, N:25.82. IR (KBr): 3459, 3349, 3251, 1649, 1584 cm⁻¹. ¹ H-NMR (CD₃ CO₂ D,70° C.): 9.05 (d, 1H, j=5.4 Hz), 8.71 (d, 2H, j=8.8 Hz), 8.49 (d, 2H,j=8.8 Hz), 8.08 (d, 2H, 8.8 Hz). ¹³ C-NMR (CD₃ CO₂ D, 70° C.): 167.5,167.3, 164.2, 163.8, 160.0, 143.7, 142.8, 131.4, 131.0, 130.1, 129.7,129.3, 129.2, 117.5. MS m/e: 316 (M⁺). FAB m/e: 317 (M⁺ +H).

The bis-guanyl compound (0.8 g, 0.0025 mole) is suspended in 25 mLabsolute ethanol, to which 25 mL saturated ethanolic HCl is added andthe mixture refluxed for 1 hr. After cooling, the volume is reduced to15 mL. The resulting off-white solid is filtered and washed with dryether. The salt is dried in vacuo at 80° C. for 24 hr. Yield: 1.0 g(94%).

Characterization: mp>36° C. (sublimes) . Elemental analysis calculatedfor C₁₈ H₁₆ N₆.3 HCl: C: 50.78, H: 4.49, N: 19.74; found: C: 50.85, H:4.53, N: 19.68. IR (KBr): 3356, 3249, 3007, 1684, 1609 cm⁻¹. ¹ H-NMR (D₂O/TSP/50° C.): 8.43 (d, 1H, j=5.4 Hz), 7.87 (d, 2H, j=7.8 Hz), 7.81 (d,2H, j=7.8 Hz), 7.57 (d, 4H, j=7.8 Hz), 7.44 (d, 1H, j=5 Hz). ¹³ C-NMR(D₂ O/TSP/50° C.): 162.3, 162.2, 158.9, 158.3, 155.0, 137.8, 137.0,126.5, 126.1, 125.7, 125.3, 125.1, 125.0, 113.4. MS FAB m/e: 317 (M++H).

EXAMPLE 7 Preparation of 2,4-Bis-[(4-imidazolin-2-yl)phenyl)pyrimidinehydrochloride]

After suspending the bis-imidate ester hydrochloride of Example 6 (2.1g, 0.0043 mole) in 50 mL absolute ethanol, ethylene diamine 0.06 g, 0.01mole) is added and the mixture is refluxed for 12 hr. The solvent isevaporated and the resulting solid is triturated with water. Theoff-white solid thus obtained is filtered, washed with water and dried.The free base is boiled with 800 mL of absolute ethanol and filtered toyield a beige crystalline solid. Yield: 1.3 g (94%).

Characterization: mp 337°-339° C. (dec.) (turns brown at 320° C. andblack at mp). Elemental analysis calculated for C₂₂ H₂₀ N₆ : C: 71.72,H: 5.47, N: 22.80; found: C: 71.70, H: 5.48, N: 22.75. IR (KBr): 3190.2,1615.4, 1602.6, 1575.8 cm⁻¹. ¹ H-NMR (CD₃ CO₂ D) 65° C.: 9.04 (d, 1H,j=5.4 Hz), 8.72 (d, 2H, j=8.3 Hz), 8.49 (d, 2H, j=8.8 Hz), 8.16 (d, 2H,j=8.3 Hz), 8.1 (d, 2H, j=8.8 Hz), 7.98 (d, 1H, j=5.4 Hz), 4.19 (s, 8H).¹³ C-NMR (CD₃ CO₂ D) 65° C.: 167.02, 166.8, 163.9, 163.6, 144.1, 143.0,139.4, 130.1, 130.0, 129.2, 125.5, 125.1, 117.6, 46.1. MS EI: 368.2(M⁺).

The free base (1.0 g, 0.0027 mole) is suspended in 35 mL saturatedethanolic HCl and refluxed for 1 hr (not all the solid is dissolved).The solvent is reduced under pressure to a volume of 5-6 mL, dilutedwith dry ether and filtered, washed with dry ether and dried in vacuo at100° C. for 24 hr. Yield: 1.2 g.

Characterization: mp >360° C. (does not melt; turns brown at ca. 345°C.). Elemental analysis calculated for C₂₂ H₂₀ N₆.3 HCl: C: 52.33, H:5.19, N: 16.64; found: C 52.51, H: 5.20, N: 16.60. IR (KBr): 3405, 3060,2945, 1618, 1607, 1572. ¹ H-NMR (D₂ O/Dioxane/45° C.): 8.73 (d, 1H,j=5.5 Hz), 8.13 (d, 2H, j=7.9 Hz), 8.03 (d, 2H, j=7.9 Hz), 7.71 (m, 5H),4.02 (s, 4H), 4.01 (s, 4H). ¹³ C-NMR (D₂ O/Dioxane/45° C.): 164.7,164.5, 161.2, 158.3, 141.2, 140.2, 128.4, 128.2, 127.7, 123.6, 123.3,116.2, 44.5. MS EI m/e: 368.2 (M⁺).

EXAMPLE 8 Preparation of2,4-Bis-[(4-tetrahydropyrimidinyl-2-yl)phenyl)-pyrimidine hydrochloride]

The bis-imidate ester hydrochloride produced in Example 7 (2.1 g, 0.0043mole) is suspended in 50 mL anhydrous ethanol. Fresh distilled1,3-diaminopropane (0.74 g, 0.01 mole) is added and a clear pale yellowsolution is formed. The mixture is refluxed for 12 hr. The solvent isremoved under reduced pressure and the solid is suspended in water andmade basic, while cooling, with diluted NaOH to pH=10. The off-whitesolid thus obtained is filtered, washed with water and crystallized froman ethanol:ether mixture to yield 0.91 g (53%).

Characterization: mp=165°-66° C. IR (KBr): 3350, 3179, 3035, 2945, 1633,1575, 1438, 1367, 1197, 832, 696 cm⁻¹. ¹ H-NMR (DMSO-d₆, 35° C.): 8.96(d, 1H, j=5.4 Hz), 8.52 (d, 2H, j=8.3 Hz), 8.04 (d, 2H, j=5.4 Hz), 7.95(d, 2H, j=8.3 Hz) 3.41-3.37 (m, 8M), 1.73-1.72 (m, 4H). ¹³ C-NMR(DMSO-d₆, 35° C.) 162.9, 162.4, 158.6, 153.1, 152.7, 138.8, 138.2,138.1, 136.8, 127.7, 126.4, 115.3, 41.4, 41.3, 20.4, 20.3. MS m/e: 396(M⁺).

The free base (0.6 g, 0.0015 mole) is heated in a 10 mL saturatedethanolic HCl solution for 2 hr, concentrated to 2 mL, and trituratedwith dry ether. The precipitated solid is filtered, washed with ether,and dried in vacuo at 65° C. for 24 hr to yield 0.63 g (82%).

Characterization: m.p 267°-68° C. Elemental analysis calculated for C₂₄H₂₄ N₆.3 HCl: C: 55.97, H: 5.48, N: 16.32; found: C: 55.90, H: 5.52, N:16.27. IR(KBr): 3425, 3179, 3025, 1640, 1620, 1574, 1400, 1013, 832,693cm⁻¹. ¹ H-NMR (CD₃ SOCD₃ /45° C.): 10.5 (s, 2H), 10.43 (s, 2H), 9.08 (d,1H, j=5.4 Hz), 8.68 (d, 3H, j=8.3 Hz), 8.55 (d, 2H, j=8.3 Hz), 8.21 (d,1H, j=5.4 Hz), 8.08 (d, 2H, j=8.4 Hz), 8.03 (d, 2H, j=8.8 Hz), 3.52 (m,6H), 2.0 (m, 4H). ¹³ C-NMR: (CD₃ SOCD₃ /40° C.): 162.2, 161.7, 159.2,158.5, 158.3, 141.0, 139.9, 130.5, 130.3, 128.5.128.2, 128.0, 127.4,116.44, 38.9, 17.6.

EXAMPLE 9 Preparation of 2-phenyl-4-(4-bromophenyl)-pyrimidine

Benzamidine hydrochloride (4.7 g, 0.03 mole) and1-dimethylamino-3-dimethylimonio-1- (4-bromophenyl) -1-propeneperchlorate are allowed to react as described above in Example 4 for thepreparation of 2,4-Bis (4-bromophenyl) -pyrimidine. After work-up andrecrystallization from CHCl₃ :ethyl ether (1:3 ), 7.2 g (72%) of a whitecrystalline solid is obtained which melted at 107°-08° C. IR(KBr) 2925,1597, 1562, 1540, 1427 cm⁻¹. ¹ H-NMR: (CDCl₃) 8.65 (d, 1H, j=5.3 Hz),8.55-8.52 (m, 2H), 8.02 (d, 2H, j=8.3 Hz), 7.6 (d, 2H, j=8.8 Hz),7.5-7.46 (m, 3H), 7.44 (d, 1H, j=5.3 Hz). ¹³ C-NMR (CDCl₃): 164.6,162.5, 157.9, 137.6, 135.7, 132.1, 130.8, 128.6, 128.5, 128.2, 125.6,114.1. MS m/e: 311 (M⁺).

EXAMPLE 10 Preparation of 2-phenyl-4-(4-cyanophenyl)-pyrimidine

2-Phenyl-4-(4-bromophenyl)-pyrimidine (6.2 0.03 mole), copper (I)cyanide (2.79 g, 0.03 mole) and 30 mL of DMF are allowed to reflux for30 hr. After working-up the mixture as described in Example 5, andrecrystallization from ethyl ether: CHCl₃ (3:1) a white crystallinesolid is obtained. Yield: 2.3 g (55%).

Characterization: mp 125°-126° C. IR (KBr): 2235, 2277, 1592, 1562, 1425cm⁻¹. ¹ H-NMR (DMSO-d₆ /90° C.): 9.0 (d, 1H, j=5.3 Hz), 8.5-8.45 (m,2H), 8.4 (d, 2H, j=8.3 Hz), 8.04 (d, 1H, j=5.3 Hz), 8.01 (d, 2H, j=8.8Hz), 7.55-7.53 (m, 3H). ¹³ C-NMR (DMSO-d₆ /90° C.): 163.4, 161.0, 159.0,140.0, 136.9, 132.8, 130.9, 127.8, 118.3, 115.7, 113.3. MS m/e: 257(M⁺).

EXAMPLE 11 Preparation of2-phenyl-4-(4-imidazolin-2-yl)-phenylpyrimidine hydrochloride

A solution of 2-phenyl-4(-cyanophenyl)-pyrimidine (1.35 g, 0.0005 mole)in dry ethanol is saturated with anhydrous HCl, and the mixture isstirred for 3 days at room temperature. The resulting imidate esterhydrochloride is isolated and dried in vacuo as described above inExample 6. The imidate is allowed to react with ethylene diamine asdescribed above in Example 7, and yields 0.8 g (70%) of white solidwhich melts at 200°-02° C. after recrystallization from ethanol.

Characterization: IR (KBr): 3176, 2925, 2865, 1606,1562, 1422 cm⁻¹. ¹H-NMR (CDCl₃ /40° C.): 8.84 (d, 1H, j=5.5 Hz), 8.8-8.55 (m, 2H), 8.25(d, 2H, j=8.6 Hz), 7.95 (d, 2H, j=8.6 Hz), 7.6 (d, 1H, j=5.5 Hz), 3.83(s, 4H). ¹³ C-NMR (CDCl₃ /50° C.): 163.3, 162.9, 162.1, 158.5, 139.7,137.1, 132.9, 130.6, 128.4, 127.7, 127.5, 126.7, 115.0, 49.5. MS m/e:299 (M⁺).

The free base is converted into the hydrochloride salt by standardprocedures to yield a white solid (85%) . Characterization: mp>300° C.IR(KBr): 3033, 2876, 2710, 1607, 1587 cm⁻¹. ¹ H-NMR (DMSO-d₆ /50° C.):1125 (s, 2H), 8.95 (d, 1H, j=5.5 Hz), 8.54-8.44 (m, 2H), 8.52 (d, 2H,j=8.6 Hz), 8.37(d, 2H, j=8.6), 8.15 (d, 1H, j=5.5 Hz) 7.75 (s, 1HNH)7.55-7.53 (m, 3H), 4.02 (s, 4H). ¹³ C NMR (DMSO-d₆ /50° C.): 163.9,163.3, 161.1, 158.7, 141.2, 136.8, 130.7, 129.4, 127.3, 124.0, 115.6,44.2. Elemental analysis calculated for C₁₉ H₁₅ N₄.2HCLO.5H₂ O: C:59.85, H: 4.75, N: 14.69; found: C: 60.02, H: 4.83, N: 14.94.

EXAMPLE 12 Biological Evaluation

                  TABLE 1                                                         ______________________________________                                               DNA    Topoisomerase   G. lamblia                                      Compound binding.sup.a                                                                           G. lamblia.sup.b                                                                        P. Carinii.sup.c                                                                     IC.sub.50.sup.d                           ______________________________________                                        Pentamidine                                                                            12.8     --        >100    2.6                                       Saline   --       --        --      --                                        1        21.5     >100      20      2.0                                       2        22.7       50      30      3.0                                       3        25       >100      20      0.79                                      4        0.6       100      --      2.0                                       5        13.9      200      no      36.7                                      ______________________________________                                         Compounds:                                                                    1: 2,4Bis(4-guanyl)-pyrimidine hydrochloride                                  2: 2,4Bis[(4imidazolin-2-yl)phenyl]pyrimidine hydrochloride                   3: 2,4Bis[(4tetrahydropyrimmidinyl-2-yl)phenyl]pyrimidine hydrochloride       4: 2phenyl-4-[4(imidazolin-2-yl)phenyl]pyrimidine hydrochloride               5:                                                                            2(4-[Ni-propylguanyl]phenyl)4-(2-methoxy-4-[Ni-propylguanyl]phenyl)pyrimi    ine                                                                            .sup.a Increase in thermal melting of poly dA.dT. See, W. Wilson, et al.,     Biochemistry 32:4098 (1993).                                                  .sup.b Inhibition of topoisomerase II isolated from G. lamblia.               Correlation of topoisomerase II inhibition with antiGiardia lamblia           activity. See, C. Bell, et al., Antimicrob. Agents Chemother. 37:2668         (1993).                                                                       .sup.c Inhibition of topoisomerase II isolated from P. carinii. See, C.       Dykstra, et al., J. Protozool. 38:78S (1991).                                 .sup.d 50% Inhibitory concentration against G. lamblia, P. carinii            topoisomerase. See, Bell, et al., supra.                                 

                  TABLE 2                                                         ______________________________________                                        In vivo Activity Against Pneumocystis carinii in Rats                         Compound mg/Kg per day Toxicity cyst/g Lung                                   ______________________________________                                        Pentamidine                                                                            10.0           2+      --                                            Saline   --            0        100%                                          1        10.0           1+      0.8%                                          1        5.0           0        2.4%                                          2        5.0           0        2.4%                                          3        2.5           +++      85.2%                                         4        5.0           +        21.1%                                         5        2.5           --       1.0%                                          ______________________________________                                         Compounds:                                                                    1: 2,4Bis(4-guanyl)pyrimidine hydrochloride                                   2: 2,4Bis[(4imidazolin-2-yl)phenyl]pyrimidine hydrochloride                   3: 2,4Bis[(4tetrahydropyrimmidinyl-2-yl)phenyl]pyrimidine hydrochloride       4: 2phenyl-4-[4(imidazolin-2-yl)phenyl]pyrimidine hydrochloride               5:                                                                            2(4-[Ni-propylguanyl]phenyl)4-(2-methoxy-4-[Ni-propylguanyl]phenyl)pyrimi    ine                                                                       

                  TABLE 3                                                         ______________________________________                                        Inihibition of C. Parvum                                                      Compound      mg/kg/day % efficacy                                            ______________________________________                                        1             25        50                                                    1             5         68                                                    1             0.1       30                                                    ______________________________________                                         1: 2,4Bis(4-guanyl)-pyrimidine hydrochloride                             

EXAMPLE 13 2-(4-Bromophenyl)-4-(2-methoxy-4-bromophenyl)pyrimidine

To a stirred suspension of 3-dimethylamino-1(4-bromophenyl) propenone(14.1 g, 0.05 mole) and bromobenzamidine benzenesulfonate (17.2 g, o.51mole) in 75 mL absolute ethonal is added sodium ethoxide (0.1 mole, from2.3 g Na) in 70 mL absolute ethanol. The mixture is heated at reflux for24 hr (TLC monitored) and the solvent distilled. The residue istriturated with 100 mL of water, and the remaining solid precipitate isfiltered, washed with water, dried and redissolved in 200 mL chloroformdried over Na₂ SO₄ (anhydrous). The excess solvent is distilled and theresidue is crystallized from CHCl₃ :ether (1:4), to yield 13.2 g of anoff-white crystalline solid (62%) having amp of 153°-5° C.

Characterization: IR(KBr) 3040, 2920, 1592, 1560, 1433, 1387, 1235,1039, 859, 807 cm⁻⁸. ¹ H NMR (CDCl₃), 8.74 (d, 1H, j=8.8), 8.10 (d, 1H,j=8.3), 7.83 (d, 1H, j=5.4), 7.61 (d, 2H, j=8.3), 7.28 (d, j=1.95), 7.17(s, 1H), 3.91 (s, 3H). ¹³ C NMR (CDCl³) 163.4, 161.6, 158.6, 157.1,136.9, 132.3, 131.7, 129.7, 125.7, 125.3, 125.1, 124.4, 119.6, 115.1,55.9. MS:m/e 420.

EXAMPLE 14 2-(4-Cyanophenyl)-4-(2-methoxy-4-cyanophenyl)pyrimidine

A suspension of the dibromo compound of Example 13 (8.4 g, 0.02 mole)and copper(I)cyanide (4.45, 0.05 mole) in 40 mL dry DMF is heated atreflux under nitrogen for 30 hr (TLC followed). The excess DMF isdistilled under vacuum and the residue triturated with 100 mL water andstirred with 500 mL 10% sodium cyanide (aqueous) for 1 hr, filtered,washed with water and dried. The solid is subjected to soxlet extractionwith acetone (24 hr) followed by chromatography over neutralaluminumoxide, elution with ether:CHCl₃ (8:2) to chloroform, to yield awhite crystalline solid. Recrystallized from CHCl₃ :ether (1:4) yielded2.5 g of a white solid (40%) having amp 239°-240°C.

Characterization: IR(KBR) 3085, 2229, 1579, 1556, 1406, 1274, 1027, 819cm¹. ¹ H NMR (CDCl₃) 8.88 (d, III, j=4.4), 8.65 (d, 2H, j=8.3), 8.3 (d,2H, j=8.3), 7.94 (d, 1H, j=4.4), 7.79 (d, 2H, j=8.3), 7.46 (dd, IH,J=8.3, J=1.4), 7.3(s, 1H), 3.99 (s, 3H). ¹³ C NMR (CDCl₃) 162.9, 161.0,158.1, 157.6, 141.7, 132.3, 132.0, 130.5, 124.9, 120.6, 118.7, 118.2,115.0, 114.2, 56.2. MS:m/e 312. Analysis calculated for C₁₉ H₂ N₄ O: C:73.06, H: 3.87, N: 17.93; found: C: 72.93, H: 3.81, N: 17.88.

EXAMPLE 152-(4-[Imidazolin-2-yl]phenyl)-4-(2-methoxy-4-[imidazolin-2-yl]phenyl)pyrimidine

A stirred suspension of dinitrile (0.003 mole, 0.939) in 80 mL absoluteethanol is saturated with dry HCl gas at 0° C. and stirred for 3 days.The reaction mixture is diluted with 200 mL dry ether and the solidfiltered, washed with dry ether, and dried in vacuum for 6 hr to obtain1.3 g (85%). The imidate ester (0.779, 0.002 mole) in 20 mL dry ethanoland ethylene diamine (0.35 g, 0.006 mole) is heated at gentle reflux for12 hr and the solvent is removed by distillation. The residue is dilutedwith 30 mL water and basified with 1N NaOH to pH 10 with externalcooling. The white solid is filtered, washed with water, dried andrecrystallized from hot ethanol to yield 0.58 g (74%) with amp of150°-151° C.

Characterization: IR(KBr) 3375, 3214, 2938, 2866, 1606, 1567, 1429,1275, 1233, 1027, 986 cm⁻¹. ¹ H NMR (DMSO d₆ /45° C.) 8.93 (d, 1H,j=5.4), 8.51 (d, 2H, j=8.3), 8.21 (d, 1H, j=7.8), 8.0 (d, 2H, j=7.8),7.98 (d, 1H, j=2.4), 7.67 (s, 1H), 7.63 (d, 2H, j=7.8), 3.97 (s, 3H),3.67 (s, 4H), 3.65 (s, 4H). ¹³ C NMR (DMSO d₆ /45° C.) 163.2, 163.0,162.7, 161.4, 157.6, 157.5, 138.8, 134.0, 132.50, 130.3, 127.4, 127.3,126.7, 119.7, 119.5, 110.8, 55.8, 49.5. MS m/e 398.

The free base (0.4 g, 0.001 mole) in 10 mL ethanol and 10 mL ethanolicHCl is heated under reflux for 1 hr, the excess solvent is distilledunder vacuum, triturated with dry ether, and the precipitated solid isfiltered, washed with dry ether, and dried in vacuum at 75° C. for 12 hrto yield 0.42 g (84%).

Characterization: IR(KBr) 3361 (br), 3113, 1617, 1590, 1258, 1024, 791cm⁻¹. ¹ H NMR (D₂ O/DMSOd₆ /45° C.) 8.78 (d, 1H, j=4.9), 8.3 (d, 2H,j=6.9), 8.08 (d, 1H, j=5.8), 7.98 (d, 1H, j=5.3), 7.88 (d, 2H, j=6.8),7.44 (d, 1H, j=8.3), 7.42 (s, 1H), 4.1 (s, 4H), 4.08 (s, 4H). ¹³ C NMR(D₂ O/DMSOd₆) 166.3, 166.0, 162.7, 162.0, 159.6, 159.0, 143.2, 132.8,130.8, 129.8, 126.1, 124.8, 122.1, 121.7, 112.8, 57.5, 45.9. Analysiscalculated for C₂₃ H₂₂ N₆.3HCl.5H₂ O: C: 51.64, H: 5.27, N: 15.71;found: C: 51.33, H: 5.41, N: 15.63.

EXAMPLE 16 2-(4-[Guanyl]phenyl)-4-(2-methoxy-4-[quanyl]phenyl)pyrimidine

The dinitrile (0.85 g, 0.0027 mole) is suspended in 35 mL of absoluteethanol and saturated with dry HCl 0° C. and stirred for 4-5 days atroom temperature. The imidate ester, a white precipitate (1.2 g, 0.0023mole), is filtered and dried in vacuum. The dry solid is suspended in 30mL of absolute ethanol, saturated with dry ammonia, and stirred for 2days. The solvent is removed under vacuum and the residue suspended inice-water, basified with 1N NaOH to pH 10, and the precipitate filtered,dried and crystallized from ethanol to yield 0.68 g (73%) of a whitecyrstalline solid having a mp 148°-149° C.

Characterization: IR(KBr) 3380, 3290, 3212, 1645, 1570, 1420, 1420,1256, 1185, 1026, 829 cm⁻¹. ¹ H NMR (DMSOd₆ /D₂ O) 8.84 (d, 1H, j=4.4),8.42 (d, 2H, j=8.4), 8.09 (d, 1H, j=4.4), 7.9 (d, 1H, j=5.2), 7.66 (d,2H, j=8.4), 7.53 (brd, 1H), 7.47 (d, 1H, j=8.8). ¹³ C NMR (DMSOd₆ /D₂ O)163.8, 163.5, 163.3, 162.2, 158.3, 158.2, 139.8, 139.4, 138.2, 131.1,128.2, 127.6, 127.3, 120.5, 119.7, 111.1, 56.5. MS m/e 346.

The free base (0.55 g, 0.0016 mole) in 10 mL absolute ethanol issaturated with dry HCl, stirred at room temperature for 5-6 hr, dilutedwith dry ether, and the resultant precipitate filtered, dried in vacuumfor hr at 80° C., to yield 0.65 g (75%) with amp of 255°-257° C.

Characterization: IR(KBr) 3380, 3270, 3137, 1677, 1597, 1257, 1019, 735cm⁻¹. ¹ H NMR (DMSO₆) 9.79 (s, 2H), 9.65 (s, 2H), 9.49 (s, 2H), 9.44 (s,2H), 9.0 (d, 1H, j=6.8), 8.6 (d, 2H, j=8.4), 8.25 (d, 1H, j=8.0), 8.04(m, 3H), 7.77 (s, 1H), 7.67 (d, 1H, j=8.0). ¹³ C NMR (DMSOd₆) 165.4,164.9, 162.1, 161.0, 158.2, 157.6, 141.8, 131.1, 130.9, 129.8 129.7,128.7, 120.0, 120.7, 120.5, 112.4, 56.6. Analysis calculated for C₁₉ H₁₈N₆ O.3HCL.1.5H₂ O: C: 47.26, H: 5.01, N: 17.4; found: C: 47.26, H: 5.21,N: 17.18.

EXAMPLE 172-(4-[N-i-Propylguanyl]phenyl)-4-(2-methoxy-4-[N-i-propylguanylphenyl]pyrimidine

Distilled isopropyl amine (0.44 g, 0.00075 mole) is added to asuspension of the imidate ester (1.4 g,0.0025 mole) in 20 mL absoluteethanol. After 3 hr of stirring the solution becomes clear; stirring iscontinued overnight at room tempture. The excess ethanol in distilledwater is added, and the solid which separated is filtered, washed withdeionized water, dried and recrystallized from ethanol:ether (1:3) toyield 0.80 g (758), mp 179°-180° C.

Characterization: IR(KBr) 3257, 3058, 2966, 1597, 1566, 1429, 1386,1251, 1183, 801 cm⁻¹. ¹ H NMR (DMSOd₆ /D₂ O) 8.9 (d, 1H, j=4.9), 8.46(d, 2H, j=8.5), 8.12 (d, 1H, j=8.5), 7.94 (d, 1H, j=5.5), 7.85 (d, 7.48(s, 1H), 7.46 (d, 1H, j=4.9), 3.96 (s, 3H) 3.82 (brm, 2H), 1.15 (d, 6H,j=6.7), 1.13 (d, 6H, j=6.1). ¹³ C NMR (DMSOd₆ /D₂ O) 162.8, 161.6,157.5, 157.2, 157.1, 141.0, 139.3, 138.2, 130.0, 127.2, 126.8, 126.0,119.5, 119.1, 110.4, 55.8, 43.7, 22.8. MS m/e 430.

Free base (0.66 g, 0.0015 mole) in 5 mL ethanol and 10 mL ethanol HCl isheated for 30 min, the excess ethanol is distilled, the residue isdiluted with dry ether (50 mL), filtered, washed with dry ether, anddried in vacuum at 60° C. (12 hr) to yield 0.75 g (79%) mp 224°-226° C.

Characterization: IR(KBr) 3422, 3218, 3068, 1667, 1619, 1571, 1394,1264, 1129, 1003, 738 cm⁻¹. ¹ H NMR (D₂ O/DMSO/45° C.) 8.95 (d, 1H,j=5.4), 8.55 (d, 2H, j=8.3), 8.18 (d, 1H, j=8.79), 8.0 (d, 1H, j=5.4),7.83 (d, 2H, j=8.3), 7.45 (s, 1H), 7.44 (d, 1H, j=5.4), 3.96 (br, 2H),3.89 (s, 3H), 1.29 (d, 6H). ¹³ C NMR (D₂ O/DMSO/45° C.) 163.0, 162.4,162.1, 158.9, 158.3, 142.0, 132.74, 131.9, 131.9, 131.5, 130.1, 129.3,128.8, 121.4, 121.2, 112.6, 57.0, 46.0, 46.0, 21.6. Analysis calculatedfor C₂₅ H₃₀ N₆ O.3HCl.H₂ O: C: 54.00, H: 6.34, N: 15.32; found: C:53.87, H: 6.41, N: 15.46.

EXAMPLE 18 5-Methyl-2,4-bis(4-bromophenyl)pyrimidine

A mixture of 4-bromopropiophenone (21.3 g, 0.1 mole) andN,N-dimethylformamide dimethyl acetal (23.8 g, 0.2 mole) is refluxed for6-7 hr with careful distillation of the methanol produced by thereaction, and the excess DMF-acetal is distilled. The residual mass issubjected to vaccumm distillation to yield 18.7 g (70%) of a dark brownthick oil which solidifies on standing, mp 37°-42° C.

Characterization: ¹ H NMR (CDCl₃) 7.47 (d, 2H, j=8.3), 7.28 (d, 2H,j=8.3), 6.82 (s, 1H), 3.05 (s, 6H), 2.11 (s, 3H). ¹³ C NMR (CDCl₃)195.3, 156.4, 142.7, 130.9, 129.8, 123.1, 105.8, 43.1, 10.9. MS: m/e268.

Sodium ethoxide (0.06 mole), (prepared from 1.38 g sodium in 75 mLabsolute ethanol) is gradually added to a stirred suspension ofp-bromobenzamidine benzenesulfonate (10.7 g, 0.03 mole), and3-dimethylamino-1-(4-bromobenzoyl)-2-methylpropen-1-one (8.04 g, 0.03mole) in 75 mL absolute ethanol, and the reaction mixture is heatedunder reflux for 12-16 hr (TLC monitored). Solvent is distilled and theresidue is treated with 150 mL water. The resulting solid is filtered,washed with water and dried. The product is dissolved in 250 mLchloroform, dried over anhydrous sodium sulfate, filtered, concentratedand recrystallized from chloroform:ether (1:4) to yield 7.75 g (64%) ofa white crystallized solid, mp 136°-137° C.

Characterization: IR(KBr) 2381, 2346, 1588, 1533, 1484, 1429, 1099,1009, 858, 756 cm⁻¹. ¹ H NMR (CDCl₃) 8.63 (s, 1H), 8.34 (d, 2H, j=8.8),7.63 (d, 2H, j=8.8), 7.57 (d, 4H, j=8.8), 2.37 (s, 3H). ¹³ C NMR (CDCl₃)163.8, 161.7, 159.5, 137.1, 136.5, 131.6, 130.7, 129.6, 125.7, 125.1,124.0, 17.0. MS: m/e 404.

EXAMPLE 19 5-Methyl-2,4-bis(4-cyanophenyl)pyrimidine

A mixture of 5-methyl-2,4-bis(4bromophenyl)pyrimidine (8.08 g, 0.02mole) and copper(I) cyanide (4.45 g, 0.05 mole) in 35 mL dry DMF isrefluxed under nitrogen for 40 hr (TLC monitored), the excess DMF isdistilled under vacuum using a water aspirator. The residual mass isdiluted with water and poured into 200 mL 10% NaCN solution, stirred for2-3 hr, filtered, washed thoroughly with water, dried and subjected tosoxlet extraction using acetone. The acetone is distilled and theresidue dissolved into 75 mL CHCl₃ and chromatographed over analuminumoxide column, eluted with ether to 80:20 CHCl₃ :ether to yield awhite crystalline solid (2.8 g, 48%), mp 194°-195° C.

Characterization: IR(KBr) 2226, 1608, 1581, 1509, 1426, 1211, 1110,1073, 971, 906, 794 cm⁻¹. ¹ H NMR (CDCl₃ 8.78 (s, 1H), 8.6 (d, 2H,j=8.3), 8.3 (4H), 7.77 (d, 2H, j=8.3), 2.45 (s, 3H). ¹³ C NMR (CDCl₃)163.2, 160.9, 160.0, 142.2, 141.3, 132.3, 132.2, 129.7, 128.5, 126.9,118.7, 118.3, 113.9, 113.4, 16.9. MS: m/e 296. Analysis calculated forC₁₉ H₁₂ N₄ : C: 77.0, H:4.08, N: 18.90; found: C: 69.92, H: 4.11, N:18.86.

EXAMPLE 20 5-Methyl-2,4-bis-(4-[imidazolin-2-yl]phenyl)pyrimidine

The dinitrile (0.0025 mole, 0.75 g) in 40 mL absolute ethanol issaturated with dry HCl gas at 0° C., stirred at room temperature for 3-4hr, and monitored by disappearance of nitrile adsorption by IR. Thereaction mixture is diluted with dry ether (100 mL), filtered, and thewhite solid is washed with dry ether and dried in vacuum for 3-4 hr toyield 1.1 g (89%). The imidate ester 1.1 g (0.0022 mole) is suspended in25 mL absolute ethanol, ethylenediamine (0.39 g, 0.003 mole) is added,and the mixture is allowed to reflux for 12 hr. The excess solvent isdistilled and the residue triturated with ice cold water (50 mL) andbasified while cooling and stirring with 1N NaOH to pH 10). Theresulting solid is filtered and washed with water, dried andcrystallized from ethanol:ether to yield 0.63 g (75%) mp 127°-129° C.

Characterization: IR(KBr) 3392, 3288, 3166, 2971, 1602, 1549, 1421,1278, 1168, 990, 855, 801 cm⁻¹. ¹ H NMR (DMSOd₆ /35° C.) 8.85 (s, 1H),8.44 (d, 2H, j=8.5), 7.98 (t, 4H), 7.83 (d, 2H, j=6.9), 3.66 (s, 4H),3.64 (s, 4H), 2.4 (s, 3H). ¹³ C NMR (DMSOd₆ /35° C.) 163.5, 163.4,163.3, 160.5, 159.6, 139.6, 139.0, 131.3, 130.6, 128.9, 127.5, 127.1,126.6, 49.1, 49.0, 16.4. MS: m/e 382.

A solution of 0.38 g (0.001 mole) free base in 10 mL absolute ethanol istreated with 5 mL saturated ethanolic HCl, and the mixture is heatedunder reflux for 20 min. The mixture is cooled and diluted with 75 mLdry ether, and the white precipated obtained is filtered, washed withether, and dried in vacuum for 12 hr at 60°-70° C. to yield 0.48 g(83%), mp 244°-245° C.

Characterization: IR(KBr) 3446, 3108, 2954, 1600, 1377, 1284, 1071, 853cm⁻¹. ¹ H NMR (DMSOd₆ /45° C.) 9.0 (s, 1H), 8.61 (d, 2H, j=8.4), 8.39(d, 2H, j=8.4), 8.32 (d, 2H, j=8.4), 8.08 (d, 2H, j=8.4), 5.12 (br s,5H), 4.08 (s, 4H), 4.06 (s, 4H), 2.46 (s, 3H). ¹³ C NMR (DMSOd₆ /45° C.)164.2, 164.1, 162.8, 160.13, 159.8, 142.9, 142.1, 129.7, 129.3, 128.9,127.9, 123.7, 123.73, 122.9, 44.3, 16.4. Analysis calculated for C₂₃ H₂₂N₆.3HCl.H₂ O: C: 54.17, H: 5.33, N: 10.48; found: C: 53.91, H: 5.46, N:10.38.

EXAMPLE 21 2-(4-Bromobenzyl)-4-(4-bromophenyl)pyrimidine

A solution of 4-bromophenylacetonitrile (52 g, 0.25 mole) in 50 mLabsolute ethanol and 200 mL dry ether is saturated with dry HCl gas at0° C. Considerable solid precipitates, the suspension is stirredvigorously for two days at room temperature, 200 mL dry ether is added,and the imidate ester is filtered, washed with dry ether and dried invacuo at 25° C. to yield 50.0 g (75%).

Dry ammonia gas is bubbled, until saturation, to a stirred suspension ofthe above imidate ester (50 g, 0.189 mole) in 100 mL absolute ethanol at0° C. The mixture is allowed to stir at 0° C. for 4-5 hr and then fortwo days at room temperature. The excess ammonia and ethanol are removedin vacuo, the oil diluted with water and basified with 1 M NaOH to ca.pH 10. An oil separates and it is extracted with 200 mL chloroform,dried (Na₂ SO₄), and the solvent is evaporated. The solid 35 isrecrystallized from CHCl₃ :ether (1:4) to yield 33 g (77.5%), mp125°-126° C.

Characterization: IR(KBr) 3436, 3313, 3138, 3056, 2936, 1638, 1607,1489, 1441, 1419, 1167, 1070, 1013, 799, 746, 496 cm⁻¹. ¹ H NMR (CDCl₃/DMSO-d₆) 7.58 (s, 2H, 7.42 (d, 2H, j=8.1), 7.14 (d, 2H, j=8.1), 5.42(br s, 1H), 3.44 (s, 2H). ¹³ C NMR (CDCl₃ /DMSO-d₆) 165.4, 134.4, 130.8,130.3, 119.9, 77.2. MS m/e 225.

To a stirred mixture of 4-bromophenylacetamidine (11.25 g, 0.04 mole)and 1-dimethylamino-3-dimethylimonio-1-(4-bromophenyl)-1-propaneperchlorate (15.25 g, 0.04 mole) in 100 mL of dry ethanol is added 0.04mole sodium ethoxide (prepared from 0.92 g Na and 65 mL ethanol). Afterstirring for 30 min at room temperature a further equivalent of sodiumethoxide is added, and the mixture is heated under reflux for 2 hr. Thesolvent is removed under reduced pressure, and the yellow-brown residuetriturated with 150 mL water. The solid is filtered, washed with water,dried in air and recrystallized from ether:hexane (1:3) to give 12.5 g(77%) of a pale yellow crystalline solid, mp 93°-94° C.

Characterization: IR(KBr) 3031, 1587, 1569, 1541, 1486, 1440, 1381,1064, 1013, 811, 770 cm⁻¹. ¹ H NMR (CDCl₃, 35° C.) 8.67 (d, 1H, j=5.4),7.93 (d, 2H, j=8.3), 7.6 (d, 2H, j=8.79), 7.45 (d, 1H, j=5.4), 7.41 (d,2H, j=8.3), 7.28 (d, 2H, j=8.3), 4.27 (s, 2H). ¹³ C NMR (CDCl₃, 35° C.)169.5, 162.9, 158.0, 137.2, 135.5, 132.1, 131.5, 130.9, 128.6, 125.7,120.5, 113.9, 45.4. MS m/e 403 (M+-1, 100%), 404 (M+, 90%).

EXAMPLE 22 2-(4- Cyanobenzyl)-4-(4-cyanophenyl)pyrimidine

A mixture of 2- (4-bromobenzyl)-4-(4-bromophenyl)pyrimidine (8.8 g, 0.02mole) and copper(I) cyanide (4.45 g, 0.05 mole) in 25 mL dryN-methyl-2-pyrrolidone is heated under nitrogen for 3-4 hr (TLCfollowed), during which time the color changes to dark brown. Themixture is poured into 250 mL ice cold water and a brown solidprecipitated. The mixture is stirred for 2 hr with 200 mL of 10% NaCNsolution; the solid is filtered, washed with water (1 L) and dried. Thebrown solid is placed in a soxlet device and treated with ethanol for 36hr. The solvent is removed, the light 5 brown solid chromatographed overneutral aluminumoxide, elution is with ether:CHCl₃ (8:2) (20×50 mLfractions). Evaporation of the solvent yields a white solid which isdried in vacuo at 100° C. for 6-7 hr to give 2.3 g (39%), mp 155°-156°C.

Characterization: IR(KBr) 3059, 2220, 1611, 1569, 1541, 1440, 1376, 857,820, 770, 687 cm⁻¹. ¹ H NMR (CDCl₃, 35° C.): 8.8 (d, 1H, j=5.4), 8.19(d, 2H, j=8.8), 7.8 (d, 2H, j=8.8), 7.61 (d, 2H, j=8.3), 7.60 (d, 1H,j=5.4), 7.53 (d, 2H, j=8.3), 4.42 (s, 2H). ¹³ C NMR (CDCl₃, 35° C.):169.0, 162.1, 158.6, 143.4, 140.5, 132.6, 132.2, 130.0, 127.7, 118.8,118.2, 114.8, 114.5, 110.6, 45.92. MS m/e 295. Analysis calculated forC₁₉ H₁₂ N₄ : C: 77.00, H: 4.08, N: 18.90; found: C: 69.88, H: 4.12, N:18.79.

EXAMPLE 232-[4-(2-imidazolinyl)benzyl]-4[(2imidazolinyl)phenyl]pyrimidine

The bis-nitrile (2.9 g, 0.01 mole) is suspended in 150 mL absoluteethanol, cooled in an ice-salt bath and treated with dry HCl gas. Thecompound dissolves to give a clear yellow solution which is stirred atroom temperature in a closed flask for 24 hr. The imidate esterhydrochloride which precipitates is filtered and washed with 150 mL ofdry ether. A second crop of imidate ester hydrochloride is obtained fromthe filtrate. The two precipitates are combined and dried in vacuo at25° C. for 4-5 hr to yield 3.65 g (74%).

The bisimidate ester hydrochloride (1.98 0.004 mole) is suspended in25-30 mL absolute ethanol, ethylene diamine (dried by distilling fromsodium) (0.6 g, 0.01 mole) is added, and the mixture is heated underreflux for 12 hr. The solvent is removed in vacuo and the resultingsolid is triturated with water, basified while cooling with 1 N NaOH toca. pH 10, and the white precipitate thus obtained is filtered, washedthoroughly with water, dried and recrystallized from hot ethanol toyield 1.14 g (75%), mp 210° C.

Characterization: IR(KBr) 3383, 3134, 2971, 1619, 1600, 1566, 1432,1408, 1389, 1205, 982, 829 cm⁻¹. ¹ H NMR (DMSO-d₆ /60° C.) 8.79 (d, 1H,j=5.5), 8.21 (d, 2H, j=8.6), 7.96 (d, 2H, j=8.6), 7.91 (d, 1H, j=5.5),7.75 (d, 2H, j=7.9), 7.40 (d, 2H, j=7.9), 4.32 (s, 2H), 3.64 (s, 4H),3.58 (s, 4H). ¹³ C NMR (DMSO-d₆ /60° C.) 168.5, 164.1, 163.2, 161.9,158.9, 143.2, 138.2, 131.0, 129.4, 127.9, 127.8, 126.8, 124.0, 114.8,48.4, 46.5, 44.9. MS m/e 381.

The free base (1.0 g, 0.0026 mole) is suspended in 20 mL saturatedethanolic HCl and refluxed for 2 hr. The solvent is distilled and theresidue treated with dry ether. The precipitated salt is filtered,washed with ether, and dried in vacuo at 80° C. for 24 hr to yield 0.95g (73%), mp 215°-218° C. (dec.).

Characterization: IR(KBr) 3431, 3086, 2952, 1619, 1590, 1562, 1504,1442, 1361, 1274, 1626, 992, 825, 686 em⁻¹. ¹ H NMR (DMSO-d₆ /65° C.)11.14 (s, 1H), 10.84 (s, 1H), 8.87 (d, 1H, j=5.4), 8.38 (d, 2H, j=7.32),8.30 (d, 1H, j=5.4), 8.29 (d, 2H, j=8.3), 8.05 (d, 2H, j=8.3), 7.62 (d,2H, j=7.3), 4.45 (s, 2H), 4.02 (s, 4H), 3.97 (s, 4H). Analysiscalculated for C₂₃ H₂₂ N₆.3HCl.0.5H₂ O: C: 55.15, H: 5.23, N: 16.78;found: C: 55.31, H: 5.44, N: 16.56.

EXAMPLE 242(4-[tetrahydropyrimidinyl-2-yl]benzyl-4-(4-[tetrahydropyrimidinyl-2-yl]phenylpyrimidine

Freshly distilled, 3-diaminopropane (0.74 g, 0.01 mole) is added to asuspension of bis-imidate ester hydrochloride (1.98 g, 0.0004 mole) in30 mL absolute ethanol and refluxed for 12 hr. Solvent is distilledunder vacuum, the resisdue is triturated with ice/water, basified with1N NaOH to pH 10, and the precipitated solid is filtered, washed withwater, dried and recrystallized from ethanol to yield 1.0 g (63%) of anoff-white solid, mp 225°-226° C.

Characterization: IR(KBr) 3353, 3179, 2943, 1618, 1575, 1438, 1367,1317, 1196, 832 Cm⁻¹. ¹ H NMR (DMSOd₆) 8.77 (d, 1H, j=5.4), 8.17 (d, 2H,j=8.8), 7.90 (d, 1H, j=5.4), 7.89 (d, 2H, j=8.79), 7.67 (d, 2H, j=8.3),7.42 (d, 2H, j=8.3), 4.3 (s, 2H), 3.4-3.35 (m, 8H), 1.8-1.72 (m, 4H). ¹³C NMR (DMSOd₆) 168.8, 162.2, 158.5, 155.7, 153.0, 141.5, 140.2, 138.0,136.9, 131.1, 129.0, 126.7, 126.5, 114.6, 44.9, 41.2, 20.1, 19.2. MS:m/e 410.

The free base (0.92 g, 0.002 mole) in 20 mL ethanolic HCl is refluxedfor 2-3 hr, the excess alcohol distilled and the residue triturated withdry ether. The solid thus obtained is filtered, washed with ether anddried under vacuum for 12 hr at 80° C. to yield 0.9 g (75%) of anoff-white crystalline solid, mp 247°-248° C.

Characterization: IR(KBr) 3425, 3271, 3179, 1620, 1574, 1440, 1376,1317, 832 cm⁻¹. ¹ H NMR (DMSOd₆) 11.18 (s, 2H), 10.9 (s, 2H), 8.9 (d,1H, j=5.5), 8.4 (d, 2H, j=8.55), 8.31 (d, 2H, j=8.55), 8.09 (d, 1H,j=5.5), 8.08 (d, 2H, j=8.5), 7.62 (d, 2H, j=8.5), 4.32 (s, 2H). Analysiscalculated for C₂₅ H₂₆ N₆.3HCl.1.5H₂ O: C: 54.89, H: 5.71, N: 15.36;found: C: 54.67, H: 5.88, N: 15.43.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. The invention is defined by the followingclaims, with equivalents of the claims to be included therein.

That which is claimed is:
 1. A method of treating Giardia lamblia in asubject in need of such treatment, comprising administering to saidsubject a compound of Formula I: ##STR8## wherein: X and Y are locatedin the para or meta positions and are each ##STR9## wherein: each R₁ isH, R₂ is H, n is O, R₃ is H, R₄ is H, R₅ is H, and R₆ is H;or apharmaceutically acceptable salt thereof, in an amount effective totreat Giardia lamblia.
 2. A method of treating Giardia lamblia in asubject in need of such treatment, comprising administering to saidsubject a compound of Formula I: ##STR10## wherein: X and Y are locatedin the para or meta positions and are each ##STR11## wherein: two R₁groups together represent C₂ alkylene, R₂ is H, n is O, R₃ is H, R₄ isH, R₅ is H, and R₆ is H;or a pharmaceutically acceptable salt thereof,in an amount effective to treat Giardia lamblia.
 3. A method of treatingGiardia lamblia in a subject in need of such treatment, comprisingadministering to said subject a compound of Formula I: ##STR12##wherein: X and Y are located in the para or meta positions and are each##STR13## wherein: two R₁ groups together represent C₃ alkylene, R₂ isH, n is O, R₃ is H, R₄ is H, R₅ is H, and R₆ is H;or a pharmaceuticallyacceptable salt thereof, in an amount effective to treat Giardialamblia.
 4. A method of treating Giardia lamblia in a subject in need ofsuch treatment, comprising administering to said subject a compound ofFormula I: ##STR14## wherein: X and Y are located in the para or metapositions and are each ##STR15## wherein: each R₁ is H, R₂ isloweralkyl, n is O, R₃ is H, R₄ is H, R₅ is H, and R₆ is H;or apharmaceutically acceptable salt thereof, in an amount effective totreat Giardia lamblia.
 5. A method of treating Giardia lamblia in asubject in need of such treatment, comprising administering to saidsubject a compound of Formula I: ##STR16## wherein: X and Y are locatedin the para or meta positions and are each ##STR17## wherein: each R₁ isH, R₂ is H, n is O, R₃ is H, R₄ is loweralkoxy, R₅ is H, and R₆ is H;ora pharmaceutically acceptable salt thereof, in an amount effective totreat Giardia lamblia.
 6. A method of treating Giardia lamblia in asubject in need of such treatment, comprising administering to saidsubject a compound of Formula I: ##STR18## wherein: X and Y are locatedin the para or meta positions and are ##STR19## wherein: two R₁ groupstogether represent C₂ alkylene, R₂ is H, n is O, R₃ is H, R₄ isloweralkoxy, R₅ is H, and R₆ is H;or a pharmaceutically acceptable saltthereof, in an amount effective to treat Giardia lamblia.
 7. A method oftreating Giardia lamblia in a subject in need of such treatment,comprising administering to said subject a compound of Formula I:##STR20## wherein: X and Y are located in the para or meta positions andare each ##STR21## wherein: two R₁ groups together represent C₃alkylene, R₂ is H, n is O, R₃ is H, R₄ is loweralkoxy, R₅ is H, and R₆is H;or a pharmaceutically acceptable salt thereof, in an amounteffective to treat Giardia lamblia.
 8. A method of treating Giardialamblia in a subject in need of such treatment, comprising administeringto said subject a compound of Formula I: ##STR22## wherein: X and Y arelocated in the para or meta positions and are each ##STR23## wherein:each R₁ is H, R₂ is loweralkyl, n is O, R₃ is H, R₄ is loweralkoxy, R₅is H, and R₆ is H;or a pharmaceutically acceptable salt thereof, in anamount effective to treat Giardia lamblia.
 9. A method of treatingGiardia lamblia in a subject in need of such treatment, comprisingadministering to said subject a compound of Formula I: ##STR24##wherein: X and Y are located in the para or meta positions, X is H, andY is ##STR25## wherein: two R₁ groups together represent C₂ alkylene, R₂is H, n is O, R₃ is H, R₄ is H, R₅ is H, and R₆ is H;or apharmaceutically acceptable salt thereof, in an amount effective totreat Giardia lamblia.
 10. A method of treating Giardia lamblia in asubject in need of such treatment, comprising administering to saidsubject a compound of Formula I: ##STR26## wherein: X and Y are locatedin the para or meta positions, X is H, and Y is ##STR27## wherein: twoR₁ groups together represent C₂ alkylene, R₂ is H, n is O, R₃ is H, R₄is loweralkoxy, R₅ is H, and R₆ is H;or a pharmaceutically acceptablesalt thereof, in an amount effective to treat Giardia lamblia.
 11. Amethod of treating Giardia lamblia in a subject in need of suchtreatment, comprising administering to said subject a compound selectedfrom the group consisting of 2,4-bis-(4-guanylphenyl)-pyrimidine,2,4-bis-(4-imidazolin-2-yl)-pyrimidine,2,4-bis-[(tetrahydropyrimidinyl-2-yl)phenyl]pyrimidine,2-(4-[N-i-propylguanyl]phenyl)-4-(2-methoxy-4-[N-i-propylguanyl]phenyl)pyrimidine,and the pharmaceutically acceptable salts thereof.